Method of protecting molten metals.



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Speeificati'onof Letters Patent lnrtqgnt'ed 14s, 1969.

No Drawing. Original application filed Hatch 5, 1989, Serial Noaefltfi." Divided and this application.

' v filed April 23, 1909. Serial No;.491' ,832. r

To all whom it may concern:

Be it known that we, \VALTEB and HILLIARY Emnmcn, citizens of. the United States, and both residents of New York, in the county of New York and State of New York, have invented a certain. new and useful Improved Method of Protecting Molten Metals, ohwhich the following is a' specification. p v p i, Our lnvention relates to the melting oi metals and protecting vsameitr'om rapid oxi-- Cit E1011 and volatihzation,.and further re-' lates to the use of the said-melted or'molten. metal to serve as a bath for the plating of iron and'steel either in sheet. or rod form, or for cast metal, and also relates to the joining or brazing of ironand steel either in sheet or rod form, or castings, and plating the same simultaneously. r

Nh'en metals such as copper and zinc are melted together to produce brass, and the heat is increased above a proper degree, the zinc rapidly oxidizes and also 'volatilizes. To prevent the volatilization and oxidation of metals of this character, we have discovered that we can use boron tri-oxid or the borates, which are of less specific gravity than that of brass, tin, zinc, lead and other metals usually used for plating purposes or for casting, and since the said materials require a higher temperature to melt the same than the metals which are to be protected and have a lighter specific gravity than the coating metal, the said materials will float upon the top, and upon the surface of the molten metals, forming a cover for same and preventing the oxygen in the air from act ing on the metals. They also prevent the volatilization of the metal when heated to a temperature at which they would normally volatilize. We have also discovered that when zinc and copper are to be fused togather, that by first reducing the boron trioxid to a fluid condition and first adding the zinc which is immediately melted, that when copper is added to the molten zinc, the copper is dissolved or melted in the Zinc which afiects the copper and causes it to melt at about or just above the temperature of. the zinc, and at a temperature considerably below that at which copper normally melts which is 1080 centigrade.

The object of our invention, therefore, is to provide means for preventing the rapid volatilization or oxidation of a molten metal by covering the same with boron trioxid or a suitable horat'e or., a suitable silicate which willfperrriit the said metals to be kept at a considerably" higher temperature than that at", which I theywould' normally oxidizeor yolatilizei p I A further object of our invention is to use this-metal or metals so protected, as a bath' injvhich we may dip iron or steel, either in I "cast, drawn-or rolled condition or in the form of a, wire to plate the same with the metal. 1

In carrying out four invention for the purpose of plating ametal, we proceed, as follows gal e select a crucible of neutral material, such as graphite, and 1nto" th1s We first place boron tri'oxid or a suitable borate or a suitable silicate in sutlicientjquantity that when melted it will cover the metal to be protected; after melting the boron trioxid or borate or silicate, we then add the metal or metals which We desire to plate with, or which we may wish to use to Withdraw from the crucible for the purpose of casting, such as zinc, and copper or tin; or a combination of metals such as zinc and copper to form brass, and after this is melt" ed it forms the bath on the surface of which floats the boron trioxid or substitute. or steel may be immersed through the boron trioxid into the molten metal, 'which'metal may be at a temperature} suiticientto volatilize or oxidize if it were not protected by the boron trioxid but which does not need to be at such a high temperature it it is desired to coat at a l wer temperature. Wlien Iron the metal to be coated is passed through the a covering material which acts on the surface of the solid metal to remove all grease or oxid and places the same incondition to receive a coating of the molten. metal, the molten metal being at a high temperature, it is more evenly and perfectly coated upon the solid metal than would otherwise be the case. Nhen the rod or. any other form of iron or steel, which is being coated, is being" withdrawn from the bath, the coated surface must pass through the material floating on the surface of the bath and be thereby coated to prevent the rapid vaporization or oxidation of the metal which forms the plattn e or cast form. 'To aidin' our description of this procedure, we will explain that we find in practice that the joining or brazing of iron or steel by means of the aforesaid described metals oralloys are dependent and cannot be consummated without plating simultan'eousl' To illustrate we vzlll proceed to deseri I the joining or brazing of a tube and the simultaneous plating there' qf. n5 We will-Ftake a sheet iron or steel tuba,

.formed by what termed by sheet,.metal A 1 workers the 'double'o'r lap seamed "borate to a fluid condition by heat' and then reducing the metalto be protected to a fluid acondition by heat beneath the surface of-the ess, 'c'ommonly'known as a water lead. tube is immersed'in the heretoforedescribed 60 molten bath and in the same mannerv as the described method of plating, and-is withdrawn in the same manner as describedfor plating, and is found to' be: brazed and This application is a companion a plication to that filed by us under date ofgl medium foriron 'orsteel, in sheet, rod,

said boron trioxid.

arch

' 5th ,'1909,bearing Serial No, 481434 and entitled Method of protecting molten met;

als. Nothing herein contained is intended to conflict with the matterscontained in the said companion application.

' Having thus described our invention, What:

we claim as new and desire to secure by Letters Patent is: I. The method of protecting molten metals consisting. in first reducing boron trioxid (B 0 to a fluid condition by heat and then reducing the metal to be protected to 'a fluid condition by heat beneath the surface of 2. The methodof protecting molten metals consisting in first reducing a suitable said horatel Signed at New York, in the county of "NewYork and State of New York, this 15th ..day of-April, A. D. 1909.

; .WALTER 1S. HOCKEY.

' HILLIARY ELDRIDGE.

Witnesses: v

G. F. QUACKINBUSH, P. HERMAN. 

